1. Field of the Invention
This invention relates to single- and multi-lumen cannulas and, more particularly, to a reinforced cannula having staggered lumen fluid outlets spaced along the length of the cannula and adapted to redirect the flow of fluid, making the cannula ideally suited for use in a variety of cardiac surgical procedures.
2. Description of the Related Art
Cannulas have long been used in a variety of applications to inject or withdraw fluid from the body. It is known to create a single-lumen cannula having wire reinforcement integrated in the body of the cannula to provide enhanced rigidity and avoid kinking of the cannula. It is also known to create a cannula having multiple lumens provided therein for delivering a variety of fluids and medications into and out of the body. However, one significant problem which exists in the art is the creation of a single cannula having multiple lumens formed therein wherein each lumen is independently reinforced so that the cannula can accommodate dramatically different fluid pressures in the adjacent cannulas without risk of collapsing the septum separating the different lumens.
Cannulas are often used in cardiac surgical procedures to conduct fluid to and from the various chambers of the heart and vessels conducting fluid to and from the heart. One desirable goal of a cardiac surgical procedure is to minimize the number of incisions which are formed in the heart and the vessels leading to and from the heart. It is especially important to minimize the number of incisions in the aorta in view of the significant fluid pressures which are experienced by this vessel during normal beating of the heart.
Another desirable goal is to minimize trauma to the heart and vessels leading to and from the heart. Pressurized fluid flowing through the cannula typically exits the cannula at a high velocity and may damage the heart, vessels or valves. In addition, the fluid flow may dislodge plaque from the walls surrounding the cannula, increasing the risk of embolic complications. Accordingly, it is important to reduce trauma to the body during a cardiac surgical procedure.